Turbomachine and method of handling turbomachine components

ABSTRACT

A turbomachine is provided and includes a blade wheel having an outer radial portion defining first and second nested pockets, a blade having a root section, which is receivable in the first pocket and thereby securable in the first pocket in circumferential and radial dimensions and an insert, which is receivable in the second pocket and configured to secure the root section in an axial dimension with positive retention.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to a turbomachine wheel with a blade retention mechanism and method of handling a turbomachine wheel with a blade retention mechanism.

Turbomachines generally have multiple stages of rotating elements that rotate around a common rotational axis. These rotating elements typically include blade wheels and blades that are attachable to outer portions of the blade wheels. During turbomachine operations, the blades aerodynamically interact with fluids passing through compressor or turbine stages and cause the blade wheel to rotate about the common rotational axis.

During assembly processes of blade wheels, the blades are typically slid into axial slots defined in the outer portions of the blade wheels and secured in place to prevent axial movement by a retention mechanism. The retention mechanism should be able to withstand the axial loads from the blade and prevent blade displacement without causing damage or deterioration of the blade materials.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the invention, a turbomachine is provided and includes a blade wheel having an outer radial portion defining first and second nested pockets, a blade having a root section, which is receivable in the first pocket and thereby securable in the first pocket in circumferential and radial dimensions and an insert, which is receivable in the second pocket and configured to secure the root section in an axial dimension with positive retention.

According to another aspect of the invention, a method of handling turbomachine components is provided and includes machining a second pocket into a face of a first pocket defined in an outer radial portion of a blade wheel, disposing an insert in the second pocket with the insert in a compressed condition, axially inserting a root section of a blade into the first pocket to secure the root section in circumferential and radial dimensions; and locking the insert in a decompressed condition to secure the root section in an axial dimension with positive retention.

According to yet another aspect of the invention, a method of handling turbomachine components is provided and includes machining a second pocket into a face of a first pocket defined in an outer radial portion of a blade wheel, disposing an insert in the second pocket with the insert in a contracted condition, axially inserting a root section of a blade into the first pocket to secure the root section in circumferential and radial dimensions and biasing the insert to remain in an extended condition to secure the root section in an axial dimension with positive retention.

These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a portion of a turbomachine blade wheel;

FIG. 2 is a perspective view of a blade of the turbomachine;

FIG. 3 is a perspective view of an insert disposable in a pocket machined in the blade wheel;

FIG. 4 is a perspective view of a pin of the insert of FIG. 3;

FIG. 5 is a perspective view of initial stages of a blade installation;

FIG. 6 is a perspective view of later stages of a blade installation;

FIG. 7 is a perspective view of a portion of a turbomachine blade wheel in accordance with alternative embodiments;

FIG. 8 is an exploded perspective view of a second insert disposable in a pocket machined in the blade wheel; and

FIG. 9 is a perspective view of later stages of a blade installation using the second insert.

The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The description provided below relates to a turbomachine blade retention/locking mechanism that can be implemented to ensure a positive blade lock during assembly and operating conditions. The retention/locking mechanism can be re-used any time the blade is repaired or replaced.

With reference to FIGS. 1-6, components of a turbomachine are provided and include a turbomachine blade wheel 10, a blade 20 and an insert 30. The blade wheel 10 may have a generally annular shape and may be configured to be rotatable about a turbomachine rotor as part of a compressor or a turbine. The blade wheel 10 has an inner radial portion substantially adjacent to the turbomachine rotor and an outer radial portion 11. The outer radial portion 11 is formed to define a first pocket 12 and a second pocket 13. The first pocket 12 extends axially along a rim 14 of the blade wheel 10 and may have a dovetail shape in cross-section. The second pocket 13 is nested within the first pocket 12. That is, the second pocket 13 is formed as a recession from a plane of an interior face 120 of the first pocket 12. A third pocket 130 may be nested within the second pocket 13 and may be formed as a recession from a plane of an interior face 131 of the second pocket 13.

The blade 20 has an airfoil section 21 and a root section 22. The airfoil section 21 is disposable to aerodynamically interact with a working fluid proceeding through a turbomachine. The airfoil section 21 extends radially outwardly from the root section 22, which is elongate and has a cross-sectional shape that complements the shape of the first pocket 12 in cross-section. The root section 22 is thus configured to be axially inserted into and receivable in the first pocket 12. When received in the first pocket 12, the root section 22 is securable in circumferential and radial dimensions relative to the turbomachine rotor and the blade wheel 10. The insert 30 is receivable in the second pocket 13 and is configured to secure the root section 22 in the axial dimension relative to the turbomachine rotor and the blade wheel 10 with positive retention.

Although not shown in the drawings, it is to be understood that the blade wheel 10 may be formed to define multiple nested pocket arrangements about an entirety of the rim 14 and that multiple blades 20 may be attached to the blade wheel 10 at respective corresponding ones of the nested pocket arrangements. In this way, the blade wheel 10 may form a rotating part of a compressor stage of a compressor or a turbine stage of a turbine of the turbomachine.

The insert 30 includes an insert spine 31, opposing tongs 32, 33, a pin 34 and a retention element 36. The insert spine 31 has first and second opposite ends and the opposing tongs 32, 33 are generally plate shaped members having lateral connection portions. The lateral connection portions of the opposing tongs 32, 33 are cantileverably connected to the first and second opposite ends of the insert spine 31 such that distal portions of the opposing tongs 32, 33 can be compressed toward one another.

The pin 34 has opposing distal ends 340 and 341 and a central portion 342 defined between the opposing distal ends 340 and 341. The central portion 342 may be threaded and thus threadably engageable with complementary threading of a through-hole 320 that is defined through a first one (i.e., the radially lower one) of the tongs 32 such that the pin 34 is disposable in first and second positions. In the first position, the pin 34 is moved toward an exterior of the insert 30 such that the distal end 341 is receivable in the third pocket 130 and the distal end 340 is remote from the second one (i.e., the radially upper one) of the tongs 33. The pin 34 in the first position thereby permits the opposing tongs 32, 33 to be compressed toward one another. In the second position, the pin 34 is moved toward the second one of the tongs 33 such that the distal end 340 abuts the second one of the tongs 33 and thereby prevents the opposing tongs 32, 33 from being compressed toward one another.

The retention element 36 projects outwardly from an external plane of the second one of the tongs 33. The retention element 36 may be shaped as a flange and may be chamfered in a complementary manner to a corresponding chamfer 220 on the root section 22 of the blade 20. Thus, with the insert 30 disposed in the second pocket 13 and the root section 22 disposed in the first pocket 12, the retention element 36 is engageable with the root section 22 to axially secure the root section 22 and the blade 20 with positive retention. In accordance with embodiments, the retention element 36 may be elongate in the circumferential dimension and may be disposed on either side of a flat, grip portion 37 that is matched with a similar grip portion 38 on the first one of the tongs 32. The grip portions 37, 38 may be employed by an operator to selectively compress at least the distal portions of the opposing tongs 32, 33 toward one another.

As shown in FIG. 5, prior to the installation of the blade 20 onto the blade wheel 10 having the first pocket 12 already formed (e.g., by casting, forging and/or machining), the second pocket 13 and the third pocket 130 may be machined into the outer radial portion 11 of the blade wheel 10 such that they are sequentially nested in the first pocket 12. The insert 30 is disposed in the second pocket 13 with the pin 34 disposed in the first position. Thus, the pin 34 is moved toward an exterior of the insert 30 such that the distal end 341 is received in the third pocket 130 and the distal end 340 is remote from the second one of the tongs 33. With the pin 34 disposed in the first position, an operator may employ the grip portions 37, 38 to bias at least the distal portions of the opposing tongs 32, 33 to become compressed toward one another and to remain in that compressed condition such that the root section 22 can be axially inserted into and received in the first pocket 12 without being inhibited from doing so by the retention element 36.

Subsequently, as shown in FIG. 6, the compression of the opposing tongs 32, 33 toward one another may be released such that the insert 30 is provided in a decompressed condition whereby the retention element 36 is permitted to engage with the chamfer 220 on the root section 22 of the blade 20. At this point, the pin 34 is moved toward the second position such that the distal end 340 abuts the second one of the tongs 33. The pin 34 thus locks the insert 30 in the decompressed condition and thereby prevents the opposing tongs 32, 33 from being compressed toward one another.

At a later time, it may be necessary to remove the blade 20 from the blade wheel 10. Such removal may be accomplished by moving the pin 34 back to the first position and re-compressing the opposing tongs 32, 33 toward one another. The root section 22 of the blade 20 can then be axially withdrawn from the first pocket 12. If necessary, the insert 30 can be removed from and re-inserted into the second pocket 13 following the axial withdrawing of the root section 22. Thus, the insert 30 is configured to be re-usable.

With reference to FIGS. 7-9, other embodiments are possible in which a second insert 40 is employed to secure the blade 20 in the blade wheel 10 in the axial dimension (similarly as described above with respect to the insert 30). The details of FIGS. 7-10 include details that have already been described above and need not be described again. As shown in FIGS. 7-9, the second insert 40 includes a body 41 having an upper portion 50 and a lower portion 60 and an elastic element 70. The upper portion 50 may be a plate-shaped member with a retention element 51 that is engageable with the chamfer 220 of the root section 22 of the blade 20 to axially secure the root section 22 and the blade 20 with positive retention.

The upper portion 50 has a body and opposing faces and is formed to define a through-hole 52 (blind or fully through) extending through the body and between the opposing faces. The body of the upper portion 50 may be wedge shaped or tapered. The through-hole 52 may be threaded along an interior thereof The threading can have a uniform or varying pitch. The lower portion 60 includes a bolt 61 and a nut 62 that is integrally formed with the bolt 61. The bolt 61 has threading along an exterior thereof and is threadably engageable with the upper portion 50 to enable radial movement of the upper portion 50 between a first, contracted condition at which the upper portion 50 is proximate to the nut 62 and a second, extended condition at which the upper portion 50 is remote from the nut 62. A lower end of the blot 61 can be hexagonal, octagonal, circular, semi-circular, chordal, square, etc. The nut 62 may be hexagonal, octagonal, circular, semi-circular, chordal, square, etc. The various shapes of the upper portion 50 and the lower portion 60 (i.e., the bolt 61 and the nut 62) may serve as anti-rotation features. The elastic element 70 may be provided as a spring washer 71 or another suitable feature and is operably disposable between the upper portion 50 and the nut 62. The elastic element 70 is configured to provide a positive stop to prevent radial movement of the upper portion 50 from the second, extended condition.

In accordance with embodiments, the upper portion 50 and the lower portion 60 may each be formed to define holding elements 80. The holding elements 80 may be provided as recesses into which wrenches (e.g., Hex Keys) may be inserted by an operator whereby the operator can hold one of the wrenches still and use the other to rotate one of the upper and lower portions 50 and 60 relative to the other. Such rotation will cause the upper portion 50 to move radially relative to the lower portion 60 and the elastic element 70.

During blade 20 installation, the second insert 40 is disposed in the second pocket 13 in the first, contracted condition with the upper portion 50 proximate to the nut 62 and such that the root section 22 can be axially inserted into and received in the first pocket 12 without being inhibited from doing so by the retention element 51. The lower end of the bolt 61 can be receivable in the third pocket 130, which can be shaped to complement the shape of the lower end of the bolt 61. Subsequently, the lower portion 60 is rotated relative to the upper portion 50 such that the second insert 40 assumes the second, extended condition with the upper portion 50 then being disposed remote from the nut 62. With the second insert 40 assuming the second, extended condition, the retention element 51 is permitted to engage with the chamfer 220 on the root section 22 of the blade 20. At this point, the elastic element 70 provides the positive stop to prevent radial movement of the upper portion 50 from the second, extended condition.

At a later time, it may be necessary to remove the blade 20 from the blade wheel 10. Such removal may be accomplished by rotating the lower portion 60 relative to the upper portion 50. This causes the second insert 40 to re-assume the first, contracted condition and allows the root section 22 of the blade 20 to be axially withdrawn from the first pocket 12. If necessary, the second insert 40 can be removed from and re-inserted into the second pocket 13 following the axial withdrawing of the root section 22. Thus, the second insert 40 is configured to be re-usable.

In accordance with the embodiments of FIGS. 1-6 and FIGS. 7-9, anti-rotation features may be further provided. Such anti-rotation features may include, but are not limited to, the elongation of the retention elements 36, 51, the first pocket 12 and the insert 30/second insert 40 being non-circular (e.g., oval-shaped, elliptical, hexagonal, octagonal, square, semi-circular, circular, etc.) and/or the first pocket 12 being formed with a slot and the insert 30/second insert 40 being provided with a key that is receivable in the slot. Also, a depth of the first, second and third pockets 12, 13 and 130 may be variable with the insert 30/second insert 40 being provided with complementarily varying heights.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. 

1. A turbomachine, comprising: a blade wheel having an outer radial portion defining first and second nested pockets; a blade having a root section, which is receivable in the first pocket and thereby securable in the first pocket in circumferential and radial dimensions; and an insert, which is receivable in the second pocket and configured to secure the root section in an axial dimension with positive retention.
 2. The turbomachine according to claim 1, wherein the insert comprises: a body having a spine and opposing tongs; and a pin, which is engageable with a first one of the tongs such that the pin is disposable in a first position, at which the opposing tongs are compressible toward one another, and in a second position, at which the opposing tongs are prevented from being compressed toward one another; and a second one of the tongs having a retention element, which is engageable with the root section to axially secure the root section with positive retention.
 3. The turbomachine according to claim 2, wherein the opposing tongs have grip portions at complementary sections thereof.
 4. The turbomachine according to claim 2, wherein the pin comprises: opposing distal ends; and a threaded central portion, which is threadably engageable with the first one of the tongs.
 5. The turbomachine according to claim 2, wherein the root section has a chamfered portion, which is engageable with the retention element.
 6. The turbomachine according to claim 1, wherein the insert comprises: a body having an upper portion and a lower portion, which are engageable with one another to enable radial movement of the upper portion; and an elastic element configured to provide a positive stop to prevent radial movement of the upper portion; and the upper portion having a retention element, which is engageable with the root section to axially secure the root section with positive retention.
 7. The turbomachine according to claim 6, wherein the upper and lower portions are threadably engageable with one another.
 8. The turbomachine according to claim 6, wherein the upper and lower portions each having holding elements that enable relative rotation between the upper and lower portions.
 9. The turbomachine according to claim 6, wherein the elastic element comprises a spring washer.
 10. The turbomachine according to claim 6, wherein the root section has a chamfered portion, which is engageable with the retention element.
 11. The turbomachine according to claim 1, wherein the insert comprises an anti-rotation feature.
 12. The turbomachine according to claim 1, wherein the first and second pockets have varying depths and the insert has a complementarily varying height.
 13. A method of handling turbomachine components, comprising: machining a second pocket into a face of a first pocket defined in an outer radial portion of a blade wheel; disposing an insert in the second pocket with the insert in a compressed condition; axially inserting a root section of a blade into the first pocket to secure the root section in circumferential and radial dimensions; and locking the insert in a decompressed condition to secure the root section in an axial dimension with positive retention.
 14. The method according to claim 13, further comprising providing the insert with anti-rotation features.
 15. The method according to claim 13, further comprising biasing the insert to remain compressed until the root section is axially inserted into the first pocket.
 16. The method according to claim 13, further comprising: unlocking the insert from the decompressed condition; compressing the insert; and axially withdrawing the root section from the first pocket.
 17. A method of handling turbomachine components, comprising: machining a second pocket into a face of a first pocket defined in an outer radial portion of a blade wheel; disposing an insert in the second pocket with the insert in a contracted condition; axially inserting a root section of a blade into the first pocket to secure the root section in circumferential and radial dimensions; and biasing the insert to remain in an extended condition to secure the root section in an axial dimension with positive retention.
 18. The method according to claim 17, further comprising providing the insert with anti-rotation features.
 19. The method according to claim 17, further comprising extending the insert by rotating a lower portion thereof, which is threadably engageable with an upper portion thereof, relative to the upper portion.
 20. The method according to claim 17, further comprising: contracting the insert; and axially withdrawing the root section from the first pocket. 